2 * BCM947xx nvram variable access
4 * Copyright (C) 2005 Broadcom Corporation
5 * Copyright (C) 2006 Felix Fietkau <nbd@openwrt.org>
6 * Copyright (C) 2010-2012 Hauke Mehrtens <hauke@hauke-m.de>
8 * This program is free software; you can redistribute it and/or modify it
9 * under the terms of the GNU General Public License as published by the
10 * Free Software Foundation; either version 2 of the License, or (at your
11 * option) any later version.
15 #include <linux/types.h>
16 #include <linux/module.h>
17 #include <linux/kernel.h>
18 #include <linux/string.h>
19 #include <linux/mtd/mtd.h>
20 #include <linux/bcm47xx_nvram.h>
22 #define NVRAM_MAGIC 0x48534C46 /* 'FLSH' */
23 #define NVRAM_SPACE 0x10000
24 #define NVRAM_MAX_GPIO_ENTRIES 32
25 #define NVRAM_MAX_GPIO_VALUE_LEN 30
27 #define FLASH_MIN 0x00020000 /* Minimum flash size */
32 u32 crc_ver_init
; /* 0:7 crc, 8:15 ver, 16:31 sdram_init */
33 u32 config_refresh
; /* 0:15 sdram_config, 16:31 sdram_refresh */
34 u32 config_ncdl
; /* ncdl values for memc */
37 static char nvram_buf
[NVRAM_SPACE
];
38 static const u32 nvram_sizes
[] = {0x8000, 0xF000, 0x10000};
40 static u32
find_nvram_size(void __iomem
*end
)
42 struct nvram_header __iomem
*header
;
45 for (i
= 0; i
< ARRAY_SIZE(nvram_sizes
); i
++) {
46 header
= (struct nvram_header
*)(end
- nvram_sizes
[i
]);
47 if (header
->magic
== NVRAM_MAGIC
)
48 return nvram_sizes
[i
];
54 /* Probe for NVRAM header */
55 static int nvram_find_and_copy(void __iomem
*iobase
, u32 lim
)
57 struct nvram_header __iomem
*header
;
64 pr_warn("nvram already initialized\n");
68 /* TODO: when nvram is on nand flash check for bad blocks first. */
71 /* Windowed flash access */
72 size
= find_nvram_size(iobase
+ off
);
74 header
= (struct nvram_header
*)(iobase
+ off
- size
);
80 /* Try embedded NVRAM at 4 KB and 1 KB as last resorts */
81 header
= (struct nvram_header
*)(iobase
+ 4096);
82 if (header
->magic
== NVRAM_MAGIC
) {
87 header
= (struct nvram_header
*)(iobase
+ 1024);
88 if (header
->magic
== NVRAM_MAGIC
) {
93 pr_err("no nvram found\n");
98 dst
= (u32
*)nvram_buf
;
99 for (i
= 0; i
< sizeof(struct nvram_header
); i
+= 4)
100 *dst
++ = __raw_readl(src
++);
101 header
= (struct nvram_header
*)nvram_buf
;
102 if (header
->len
> size
) {
103 pr_err("The nvram size according to the header seems to be bigger than the partition on flash\n");
106 if (header
->len
>= NVRAM_SPACE
) {
107 pr_err("nvram on flash (%i bytes) is bigger than the reserved space in memory, will just copy the first %i bytes\n",
108 header
->len
, NVRAM_SPACE
- 1);
109 header
->len
= NVRAM_SPACE
- 1;
111 /* proceed reading data after header */
112 for (; i
< header
->len
; i
+= 4)
113 *dst
++ = readl(src
++);
114 nvram_buf
[NVRAM_SPACE
- 1] = '\0';
120 * On bcm47xx we need access to the NVRAM very early, so we can't use mtd
121 * subsystem to access flash. We can't even use platform device / driver to
122 * store memory offset.
123 * To handle this we provide following symbol. It's supposed to be called as
124 * soon as we get info about flash device, before any NVRAM entry is needed.
126 int bcm47xx_nvram_init_from_mem(u32 base
, u32 lim
)
128 void __iomem
*iobase
;
131 iobase
= ioremap_nocache(base
, lim
);
135 err
= nvram_find_and_copy(iobase
, lim
);
142 static int nvram_init(void)
145 struct mtd_info
*mtd
;
146 struct nvram_header header
;
147 struct nvram_header
*pheader
;
151 mtd
= get_mtd_device_nm("nvram");
155 err
= mtd_read(mtd
, 0, sizeof(header
), &bytes_read
, (uint8_t *)&header
);
156 if (!err
&& header
.magic
== NVRAM_MAGIC
&&
157 header
.len
> sizeof(header
)) {
158 if (header
.len
>= NVRAM_SPACE
) {
159 pr_err("nvram on flash (%i bytes) is bigger than the reserved space in memory, will just copy the first %i bytes\n",
160 header
.len
, NVRAM_SPACE
);
161 header
.len
= NVRAM_SPACE
- 1;
164 err
= mtd_read(mtd
, 0, header
.len
, &bytes_read
,
169 pheader
= (struct nvram_header
*)nvram_buf
;
170 pheader
->len
= header
.len
;
178 int bcm47xx_nvram_getenv(const char *name
, char *val
, size_t val_len
)
180 char *var
, *value
, *end
, *eq
;
192 /* Look for name=value and return value */
193 var
= &nvram_buf
[sizeof(struct nvram_header
)];
194 end
= nvram_buf
+ sizeof(nvram_buf
);
195 while (var
< end
&& *var
) {
196 eq
= strchr(var
, '=');
200 if (eq
- var
== strlen(name
) &&
201 strncmp(var
, name
, eq
- var
) == 0)
202 return snprintf(val
, val_len
, "%s", value
);
203 var
= value
+ strlen(value
) + 1;
207 EXPORT_SYMBOL(bcm47xx_nvram_getenv
);
209 int bcm47xx_nvram_gpio_pin(const char *name
)
212 char nvram_var
[] = "gpioXX";
213 char buf
[NVRAM_MAX_GPIO_VALUE_LEN
];
215 /* TODO: Optimize it to don't call getenv so many times */
216 for (i
= 0; i
< NVRAM_MAX_GPIO_ENTRIES
; i
++) {
217 err
= snprintf(nvram_var
, sizeof(nvram_var
), "gpio%i", i
);
220 err
= bcm47xx_nvram_getenv(nvram_var
, buf
, sizeof(buf
));
223 if (!strcmp(name
, buf
))
228 EXPORT_SYMBOL(bcm47xx_nvram_gpio_pin
);
230 char *bcm47xx_nvram_get_contents(size_t *nvram_size
)
234 struct nvram_header
*header
;
242 header
= (struct nvram_header
*)nvram_buf
;
243 *nvram_size
= header
->len
- sizeof(struct nvram_header
);
244 nvram
= vmalloc(*nvram_size
);
247 memcpy(nvram
, &nvram_buf
[sizeof(struct nvram_header
)], *nvram_size
);
251 EXPORT_SYMBOL(bcm47xx_nvram_get_contents
);
253 MODULE_LICENSE("GPLv2");